Blue nevi is an uncommon pigmented lesion of dermal melanocytes. Blue Nevi are also known as blue moles and are blue-black moles that are common to people of Asian descent. It is composed of melanocytes, the cells which produce the melanin pigment, which have a spindled to epithelioid appearance. This nevus gets its name from the distinct clinical appearance because of the pigmented cells within the dermis. Malignant blue nevus is a rare melanocytic tumor of the skin arising from a preexisting cellular blue nevus. Nevi are usually present at birth. Sometimes, however, they may not appear until ages two or three. Blue nevi are believed to represent “dermal arrest in embryonal migration of neural crest melanocytes that fail to reach the epidermis:, although there is no definitive experimental evidence to support this belief. Most cases of blue nevi remain benign no matter how long they remain and are have no symptoms. More women than men are diagnosed with blue nevi. Most cases of blue nevi are identified in the twenties or later though it may develop at any age.
Blue nevi are best described as smooth-surfaced, dome-shaped papules that slowly develop from a macule to a papule. Although blue nevi are benign, they are sometimes mistaken for melanomas, especially in elderly persons. Melanomas occasionally develop in association with blue nevi. This phenomenon is usually portended by rapid growth and, occasionally, ulceration of the nevus. Blue nevi can develop at any age but are usually noticed in second decade of life or later and are twice as common in women as in men. Although rare, malignant degeneration of cellular blue nevi can occur. Symptoms of blue nevi is to composed of skin and large dilated blood vessels, the nevi do not disappear and are found on internal organs such as the stomach, liver, spleen, heart, bone, muscle, bladder, and vulva. They are easily compressible and refill after compression. Occasionally, the nevi are painful. No treatment is needed as blue naevi are harmless. However, some people with a blue naevus on an exposed part of the body ask for it to be removed for cosmetic reasons.
Causes of Blue nevi
Blue Nevi may be inherited as an autosomal dominant trait. Human traits, including the classic genetic diseases, are the product of the interaction of two genes, one received from the father and one from the mother. UVB is also the main cause of blue nevi, which affects the outer skin layers. UVB is most intense at midday when sunlight is brightest. Long-term repetitive and cumulative exposure to sunlight appears to be responsible for the vast majority of undesirable consequences of aging skin, including basal cell and squamous cell carcinomas.
Common causes and risk factors of Blue nevi:
- Intense exposure to sunlight in early life.
- Ultraviolet light B.
- Certain medications.
- Long-term repetitive.
- Bulging veins.
Signs and Symptoms of Blue nevi
In general cases where blue nevi are normal, it usually lingers in the skin and remains unchanged and asymptomatic through out the life of the person. Blue nevi may be found anywhere on the body. They usually appears on the skin of older children and teenagers, but may develop at any age. They are harmless. Symptoms of blue nevi is to composed of skin and large dilated blood vessels, the nevi do not disappear and are found on internal organs such as the stomach, liver, spleen, heart, bone, muscle, bladder, and vulva. Occasionally, the nevi are painful. Ranging in size from millimeters to several centimeters, the nevi can number from a few to hundreds.
Sign and symptoms may include the following :
- Skin lumps.
- Skin color changes.
- Skin lesion.
Treatment for Blue nevi
No treatment is needed in mild cases. However, some people with a blue naevus on an exposed part of the body ask for it to be removed for cosmetic reasons. Removal involves a small surgical excision after an injection of local anaesthetic. It takes about twenty minutes, and leaves a small scar.
Treatment may include:
- Microsurgery, is beneficial in acute cases of blue nevi.
- Sequential dry ice epidermal peeling is also suitable for the treatment of blue nevi.
- Laser Surgery surgery is a very effective treatment for blue nevi.
- Cryotherapy is also very effective in the eradication of damaged part of the skin.